2006 Galant P0431 Oxygen Sensor help

I have a 2006 Mitsubishi Galant 2.4 liter 4 cylinder car.

Question1:
How many oxygen sensors does this car have total?


Question 2:
I recently got OBDII code P0431 witch says its bank2 sensor or catalytic converter. i would like to try to change the o2 oxygen sensor first but i dont know witch one to replace. Facing the front of the car I see 4 sensors, i see 2 (one on the top and another on bottom) on the driver side of the engine....and i see another 2 (one on the top and another on bottom) on the passengers side of the engine. which one(s) should i replace?

any input or feedback would be greatly appreciated

It's right in here: The FSM Good luck, that's an easy job!

http://o2sensors.com.au/static/o2-se...-and-locations

Try this link it might help you understand what you're dealing with better, I used to use it when I was newer to cars for help

Good luck

figured it out for my 2.4 ...
the oxygen sensor locations for my 4 cylinder Galant 4G69 2.4L engine


bank 1 o2 sensor 1 - ( upstream ) - passenger side upper o2 sensor BEFORE the catalytic converter
bank 1 o2 sensor 2 - ( downstream ) - passenger side lower o2 sensor on or after the catalytic converter

bank 2 o2 sensor 1 - ( upstream ) - driver side upper o2 sensor BEFORE the catalytic converter
bank 2 o2 sensor 2 - ( downstream ) - driver side lower o2 sensor on or after the catalytic converter


hope this helps others, took me like a hour of research to figure this out, was all confusing with the downstream uppe r lower banks and all this terminology that they use that all means the same thing but different ways of saying it.

https://i.imgur.com/XTpMhL3.jpg

just to let other people know, it ended up being two catalytic converts i had to replace, yes 2, two, that was not a typo, the header catalytic converter and the one thats on the stright pipe under the card thats by the muffler. Pretty much all the trash from the main catalytic converter clogged the 2nd one. what a headache. soon as i repalced the catalytic converters i cleared the codes and the that P0431 never came back.